Bees move quickly in unpredictable directions making photography challenging. It involves guessing where they're going to land, and by the time they are in focus, they have flown off long before the shutter can get clicked! I particularly enjoy photographing their wings and love how back at the computer I can see the incredible patterns and textures which are impossible to see at the time.  I don't know about the different species, but I do love how different they all are, and how beautiful they look against the different colours and shapes of the flowers they visit.